The number of deaths due to AIDS in high-risk populations continues to increase. Nationwide approximately 25 percent of AIDS patients are intravenous (IV) drug abusers, and it is very likely that an increasingly larger number of AIDS patients receiving AZT therapy will have had a history of IV drug abuse. The major chemical treatment for IV drug abuse is daily methadone maintenance therapy, and IV drug abusers who are HIV positive represent a large number of patients who will undergo long-term treatment with both methadone and AZT. Therefore, the study of potential drug interactions is essential.

The 18 patients are patients with AIDS or ARC. Nine are control patients who are not receiving methadone and are not IV drug abusers. Nine are former IV drug abusers who have been maintained on methadone for at least 6 months and who have been receiving a constant daily dose of methadone for at least 1 month. Plasma and urine levels of methadone are determined over a 4 hour period. The dose of AZT: For the pharmacokinetic study of AZT, plasma and urine samples are taken after oral dose of AZT and an intravenous dose of AZT in the control and methadone groups.

Inclusion Criteria

Prior Medication:

Allowed:

• Oral nonabsorbable antifungal agents.

The study will include 18 patients with AIDS or HIV-related symptomatic illness as defined by the CDC classification group IVa and c2. Of these, 9 methadone recipients will have been maintained on methadone for at least 1 month and will have received a constant daily dose of 30-90 mg of methadone for at least 10 days.

Nine patients will be former intravenous drug abusers.

Exclusion Criteria

Co-existing Condition:

Patients with the following symptoms or conditions are excluded:

• Temperature > 101 degrees F.
• Ascites.
• Active opportunistic infection.

Concurrent Medication:

Excluded:

• Other inducers or inhibitors of hepatic microsomal enzymes.
• Any chronic systemic medications.

Patients with the following symptoms or conditions are excluded:

• Temperature > 101 degrees F.
• Ascites.
• Active opportunistic infection.

Prior Medication:

Excluded within 72 hours of study entry:

• All medication except oral nonabsorbable antifungal agents.
• Excluded within 2 weeks of study entry:
• Any other experimental drug.
• Drugs with known nephrotoxic potential or drugs known to cause neutropenia.
• Rifampin or its derivatives, phenytoin, or barbiturates.

Active drug or alcohol abuse.